Remove unused exception parameter from ../xplat/js/react-native-github/packages/react-native/React/CxxModule/RCTCxxUtils.mm (#54573)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/54573

`-Wunused-exception-parameter` has identified an unused exception parameter. This diff removes it.

This:
```
try {
    ...
} catch (exception& e) {
    // no use of e
}
```
should instead be written as
```
} catch (exception&) {
```

If the code compiles, this is safe to land.

Reviewed By: dtolnay

Differential Revision: D87273133

fbshipit-source-id: eb27f9e0be8e5b6a41aa4a9d0af88ef64381fe15